Biocide compositions for controlling the growth of bacteria are known. Such bacteria are found in many aqueous systems, for example natural waters, pools, and industrial systems such as cooling water systems, air washer systems, and pulp and paper mill systems. The presence of such bacteria can cause slime which can foul, plug, or corrode the system.
There a number of compounds which are used as biocides. Among them are isothiazolones such as 2-methyl-4-isothiazolin-3-one; 2,2-dibromo-3-nitrilopropionamide; thiones as 3,5-dimethyl-tetrahydro-2H-1,3,5-thiadiazine-2-thione; chlorine dioxide; dithiocarbamates such as sodium dimethyl dithiocarbamate and disodium ethylene bis-dithiocarbamate; thiocyanates such as methylene bis-thiocyanate; quaternary ammonium chlorides such as alkyl dimethyl benzyl ammonium chloride and dialkyl methyl benzyl ammonium chloride; chlorine; hypochlorite; chlorine dioxide; hydrogen peroxide; peracetic acid; glutaraldehyde; N-4-dihydroxy-alpha-oxobenzene ethanimidoyl chloride; 1-alkyl(C16-18)amino-3aminopropane acetate; bis(trichloromethyl) sulfone; 5-chloro-2-methyl-4-isothiazolin-3-one; 2-(thiocyanomethylthio)benzothiazole; and bis(trichloromethyl) sulfone; 1-(3- chloroallyl)-3,5,7-triazoniaadamatane chloride; N-4-dihydroxy-alphaoxobenzene ethanimidoyl chloride; sodium hypochlorite; 4,5-dichloro-1,2-dithio-30one; decylthioethylamine; and dodecylquandine hydrochloride.
Although numerous biocides like these have been known for many years, it is not possible to predict with any accuracy how they will interact when combined. Consequently, there is an interest in developing new biocide mixtures which provide advantages under use conditions.